The present invention relates generally to a chimney liner adaptor for protecting the open end of the annular space of a chimney flue from the ingress of undesirable elements.
It is well known that chimney caps are often desired to prevent the ingress of undesirable elements into the upper end of a chimney flue. For example, the undesirable elements may include birds, squirrels, and rain. It is also known that chimney caps are desired to prevent the egress of embers from the upper end of the chimney flue. In many chimney systems, a chimney liner is disposed within a chimney flue. For example, when a masonry chimney flue develops cracks or leaks in its side walls due to deterioration over time or other reasons, the installation of a chimney liner within the flue is a cost-effective way to repair the deteriorated flue. The hot gases and combustion products are contained within the liner. Such liners are often round conduit or pipe made of corrosion resistant material such as stainless steel.
In some chimney systems, the chimney liner is disposed within a multi-wall factory-built type chimney. Generally, a factory-built chimney is a double-walled round conduit or pipe, with the inner wall spaced from the outer wall. The inner wall is the flue for the hot gases and combustion products. The annulus formed between the two pipe walls acts as insulation, so that the outer wall stays cool enough to be installed in close proximity, e.g., within one to two (1-2) inches, of combustible materials. Also, cooling air may flow through the annulus by forced or natural convection. Some factory-built chimney pipes have three walls and/or insulation positioned between two of the walls. For example, a factory-built chimney for wood-burning fireplaces is marketed by Hearth Technologies Inc., dba Heatilator, of Mt. Pleasant, Iowa.
When a liner is installed within a factory-built chimney, another annular “inner chimney space” is formed between the outside of the chimney liner and the inside wall of the factory-built chimney. Therefore, it is desirable to permit the movement of cooling air through this inner chimney space to exit to the outside environment. However, when a chimney cap is attached to such a chimney system to prevent the ingress of undesirable elements into the chimney liner, it may block the air circulation to the inner chimney space. Chimney caps are known that permit the circulation of air to the inner chimney space. However, these known devices fail to prevent the ingress of undesirable elements into the inner chimney space. Therefore, it would be desirable to have a chimney liner adaptor that prevents the ingress of undesirable elements into the inner chimney space and also permits the use of a chimney liner cap to prevent the ingress of undesirable elements into the chimney liner.